This disclosure relates to a tool for machining a workpiece, wherein the tool comprises two tool components which are joined together by means of a joining material. Furthermore, this disclosure relates to the individual tool components of the herein presented. Still further, this disclosure relates to a method for producing the herein presented tool.
Tools, for example, drilling, turning, milling, feather keyway broaching or reaming tools, are frequently produced from different, individual tool components which are permanently joined together during production of the tool. Said different tool components are, for example, the tool shank as well as an intermediate piece for receiving a cutting insert which is fixedly connected to the tool shank. During production of the tool, said tool components are fixedly joined together by means of a joining process, in particular by means of a soldering or bonding method. Although such soldering and bonding methods are already widely known, the joining of two tool components is deemed to be difficult when the tool components are components which comprise, in each case, one or more internal coolant bores which are to be aligned with one another when the tool is in the assembled state. The joining material (e.g. soldering or bonding material), which is applied on the interface between the two tool components, frequently then passes into the interior of the inner coolant bores, which can result in clogging and consequently in the coolant bores of the tool to be produced failing to function.
Clogging of the coolant bores by the joining material stems in the majority of cases from the two tool components to be joined being moved relative to one another either manually or by machine during the joining process in order to cover the connecting faces to be joined in a uniform manner with joining material. In this case, the joining material is also distributed then on top of the coolant outlets of the internal coolant bores which are arranged on the connection faces. The blocked or clogged coolant bores consequently have to be re-bored in a production step downstream. Insofar as one of the two or both tool components are produced from carbide, the bore diameter is then, however, smaller than the original diameter of the internal coolant bore such that the effective cross section of the internal coolant bore is ultimately reduced in a disadvantageous manner.
A further problem during the joining process consists in aligning the internal coolant bores of the two tool components relative to one another. The coolant outlets of the one tool component, with the tool in the mounted state, should be aligned exactly with the coolant outlets of the other tool component. In order to ensure this during the joining process, for example a wire or another aid is inserted through the coolant bore of the one tool component into the coolant bore of the other tool component. A relative movement, as mentioned above, for improved coverage of the contact faces with joining material is then, however, no longer possible. Apart from this, it is deemed to be difficult in the majority of cases to remove the wire or the other aid again from the coolant bores after the joining process. In addition, the coolant bores of the tool components to be joined can only be aligned with respect to one another in this way when the internal coolant bores are linear bores. However, if at least one of the coolant bores is a curved or coiled bore, such alignment of the two tool components in this way is not possible.
To overcome the above-named problems, attempts are also sometimes made to blow air through the internal coolant ducts during the joining process so that they do not fill up with joining material. However, only small relative movements between the two tool components to distribute the joining material onto the contact faces can be made in the case of said method also. Then again, the joining material is blown into the internal coolant bores as a result of said purge air supply such that parts of the joining material adhere to the inside surfaces of the coolant bores, which can lead, in turn, to clogging or to a disadvantageous reduction in the effective cross section of the coolant bores.